Custom presets are where you modify the camera’s picture settings to obtain a certain “look” e.g. to make the video appear more film-like.
Black stretch will affect how black the blacks get. The darker you make the blacks the less detail you’ll have in the shadows of your picture but you’ll gain desirable contrast. Making the blacks lighter reveals more shadow detail but you lose contrast. Knee does the same thing but it only affects the highlights. Black stretch, knee, pedestal, gamma settings etc, all allow you to adjust your picture for different shooting conditions.
A quick Google search for the above terms will bring lots of results.
Custom keys are used for things like putting the camera into record stop mode and for turning on and off the zebra bars, etc. I use my two custom keys all the time and they’re set for the above functiions.
– Don
“Please take a moment to fill out your profile, including your computer system and relevant software. Help us help you.”